Snubbed truck bolster

ABSTRACT

A snubbed railway car truck wherein the friction shoes are provided with laterally extending projections which cooperate with recessed vertical faces on the bolster to limit horizontal and rocking movement of the latter relative to the side frame. Wear resulting from relative motion of the truck parts occurs on the friction shoe rather than on the side frame or bolster. Mated tapered adjustment surfaces on the friction shoes and bolster automatically compensate for wear occurring on the friction surface of the shoe so that the effectiveness of the arrangement to minimize undesirable bolster motion does not deteriorate.

United States Patent '[191 Neumann 1 Aug. 26, 1975 1 4] SNUBBED TRUCK BOLSTER Otto Walter Neumann, Chicago, Ill.

[73] Assignee: Amsted Industries Incorporated,

Chicago, 111.

221 Filed: June 4,1973

21 Appl. No.: 366,431

[75] Inventor:

[52] U.S. Cl 105/197 DB; 105/198 [51] Int. Cl. B6lf 5/12; B6lf 5/50; F16d 69/04 [58] Field of Search 105/197 D, 197 DB, 197 R,

[56] References Cited UNITED STATES PATENTS 2,378,415 6/1945 Light 105/197 DB 2,394,872 2/1946 Pierce... 105/197 DB 2,395,317 2/1946 Cottrcll 105/197 DB 2,422,201 6/1947 Lehman 105/197 DB 2,597,909 5/1952 Tack 105/197 DB Wamock 105/197 DB Takamatsu et al. 105/197 DB Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-Howard Beltran 5 7 ABSTRACT A snubbed railway car truck wherein the friction shoes are provided with laterally extending projections which cooperate with recessed vertical faces on the bolster to limit horizontal and rocking movement of the latter relative to the side frame. Wear resulting from relative motion of the truck parts occurs on the friction shoe rather than on the side frame or bolster. Mated tapered adjustment surfaces on the friction shoes and bolster automatically compensate for wear occurring on the friction surface of the shoe so that the effectiveness of the arrangement to minimize undesirable bolster motion does 'not deteriorate.

2 Claims, 8 Drawing Figures PATENTED AUG 2 81975 SHEET 1 [IF 2 SNUBBED TRUCK BOLSTER This invention relates to railway car trucks and more particularly to the snubbing arrangement therefor.

A primary object of the present invention is to provide means adapted to minimize undesirable horizontal and rocking movement of a railway truck bolster relative to the side frames such that any wear from service operation of the truck occurs on the friction shoe rather than on the side frames or bolster.

Another object is to provide bolster anti-rocking stop means that is renewable by the replacement of the friction shoe and friction plate, thereby eliminating comparatively expensive and time consuming repairs to worn side frame and bolster surfaces.

The invention is described in conjunction with the following description and drawings wherein:

FIG. 1 is a fragmentary side elevational view of a railway car truck embodying features of the present invention, portions of the structure being shown in section;

FIG. 2 is a sectional view along line 2-2 of FIG. 1;

FIG. 3 is a top plan view of a portion of a prior art railway car truck, with portions of the structure shown in section;

FIG. 4 is a view similar to FIG. 1 of another prior art truck structure;

FIG. 5 is a sectional view taken along line 55 of FIG. 2.

FIG. 6 is a view similar to FIG. 2 showing another embodiment of the invention.

FIG. 7 is a sectional view taken along line 77 of FIG. 6; and

FIG. 8 is a view similar to FIG. 7 but showing certain parts in worn condition.

Referring now to the drawings, and particularly to FIGS. 1 and 2, there is shown a portion of a railway car truck comprising a side frame, generally indicated at 10, which includes a compression member 12 and a tension member 14 interconnected by spaced columns 16 to form a window 18 adapted to receive one end of a bolster indicated generally at 20. The bolster is supported in a conventional manner by a plurality of support springs 22 which rest on the member 14.

The bolster includes opposed side walls 23 partially defining wedge-shaped pockets 24 which open outwardly toward the side frame columns 16 and have an inclined inner wedge surface 25 disposed at an angle in v A control spring 36 is disposed between the lower surface 38 of the shoe and the tension member 14, the control spring being effective to bias the shoe against the bolster wedge surface and the side frame wear plate.

In present day snubbed trucks, it is necessary that means be provided to minimize horizontal and rocking movement of the bolster relative to the side frames. One prior art arrangement for accomplishing this is shown in FIG. 3 wherein stop lugs 40 are provided on the inboard side of the side frame columns, the stop lugs presenting surfaces 42 facing outwardly directed surfaces 44 presented by bolster gibs 46. This arrangement operates satisfactorily to restrict relative motion between the side frame and bolster but has the disad vantage of costly repair when the stop lugs become worn and the clearance between the stop lugs and gibs consequently increases.

Another prior art arrangement is shown in FIG. 4, the purpose of the arrangement being to reduce horizontal angling of the bolster relative to the side frame and to reduce wear on the side frame and bolster surfaces which come into contact during service operation. In this arrangement, the bolster 20 is disposed in an opening adjacent side frame column 16 and, in the conventional manner, a friction shoe 26 is carried in a bolster pocket 24. The side frame column is provided with elongated flanges 48 having wear surfaces 50 closely adjacent spaced coplanar guide surfaces 52 on the bolster 20. However, because of the relative motion of the side frame and bolster during service, the surfaces 50 and 52 are subject to wear which causes them to lose their effectiveness as rotation stops. In order to renew their effectiveness, the surfaces must be built up by the time consuming process of welding which also requires grinding, gauging, and the like. All of this, of course, is in addition to the normal periodic replacement of worn friction shoes and wear plates.

The present invention, which overcomes the deficiencies of prior art arrangements, is illustrated in FIGS. 2 and 5. Referring to these figures, it is seen that the vertical wall 28 of the shoe, which engages the wear plate 32, is extended laterally to provide projections 54. The projections 54 present stop surfaces 56 in closely spaced relationship with oppositely facing guide surfaces 58 which are formed in recesses 59 of the bolster 20. These mutually facing surfaces 56 and 58 act as stops to minimize undesirable horizontal and rocking movement of the bolster relative to the side frame during service operation.

It should be noted, however, that the friction shoe is constantly biased against the wear plate 32 and the bolster wedge surface 25 by the control spring 36. The shoe, therefor, moves with the bolster so that there is little or no wear which can occur on surfaces 56 and 58 so as to destroy their effectiveness in controlling undesirable bolster motions. Primarily, wear occurs on vertical friction face 30 of the shoe and on the wear plate 32 with some wear also occurring on the shoe wedge face 35. When this wear exceeds a predetermined amount,-it is merely necessary to replace the friction shoes and the wear plate. The proposed arrangement, therefor, has all the advantages of prior art arrangements as to minimizing unwanted bolster motions, but also eliminates the time consuming and expensive repair and rebuilding of the side frame and bolster.

FIGS. 6, 7 and 8 illustrate a further modification of the friction shoe whereby means is provided to compensate for wear occurring on shoe friction face 30 so that the relationship between stop surface 56 and guide surface 58 remains more completely effective for substantially the life of the friction shoe.

It will be appreciated that, as wear occurs on the surfaces 30, 34 and 35, the shoe moves upwardly and outwardly in the bolster pocket. As the shoe moves outwardly, there will be an increase in the distance between stop surfaces 56 and guide surfaces 58 resulting in some slight decrease in the effectiveness of these surfaces in controlling undesirable bolster motion. Referring first to FIGS. 6 and 7, it is seen that the surface 56 of shoe wall 28 is tapered at an angle converging upwardly toward the wear plate 32. Similarly surface 58 of the bolster is tapered upwardly at an angle corresponding to the taper angle of the shoe wall. Although the specific taper angle will vary somewhat depending on the friction face areas, the spring pressure exerted on the shoe, and the materials of which the shoe and wear plate are formed, an angle of approximately 18 from the vertical can most advantageously be used, and angles greater or less than 18 will still provide a fair degree of compensation for shoe wear. In any case, the angle from the vertical must be smaller than the wedge angle of surfaces 25 and 35 so as to prevent a locking relationship from occurring. When such a taper is incorporated in the surfaces 56 and 58 of the shoe and bolster, respectively, iit will be seen from FIGS. 7 and 8 that the friction shoe, under the biasing action of control spring 36, will move upwardly and to the right as wear occurs on the friction shoe and the wear plate. As this movement occurs, the spacing between the surfaces 56 and 58 will be retained within the limits necessary for minimizing both horizontal and rocking movement of the bolster relative to the side frame.

I claim:

1. In a railway car truck: a side frame having a column partly defining a bolster opening; a bolster resiliently supported in said opening; a friction surface on said column; a wedge surface on said bolster sloping toward said friction surface; a friction shoe having a wedge surface resiliently urged into complementary engagement with said bolster wedge surface; a friction wall on said shoe having a friction face engageed with the column friction surface; said wall having lateral projections defining stop surfaces facing the bolster; and guide surfaces on the bolster parallel to and in closely spaced relationship with said stop surfaces so that horizontal and rocking movement of the bolster relative to the side frame are minimized; said shoe stop surfaces and said bolster guide surfaces tapering upwardly toward the column friction surface.

2. In a railway car truck according to claim 1, wherein the tapered surfaces have an angle relative to vertical which is smaller than the angle of the sloping wedge surfaces of the friction shoe and bolster. 

1. In a railway car truck: a side frame having a column partly defining a bolster opening; a bolster resiliently supported in said opening; a friction surface on said column; a wedge surface on said bolster sloping toward said friction surface; a friction shoe having a wedge surface resiliently urged into complementary engagement with said bolster wedge surface; a friction wall on said shoe having a friction face engageed with the column friction surface; said wall having lateral projections defining stop surfaces facing the bolster; and guide surfaces on the bolster parallel to and in closely spaced relationship with said stop surfaces so that horizontal and rocking movement of the bolster relative to the side frame are minimized; said shoe stop surfaces and said bolster guide surfaces tapering upwardly toward the column friction surface.
 2. In a railway car truck according to claim 1, wherein the tapered surfaces have an angle relative to vertical which is smaller than the angle of the sloping wedge surfaces of the friction shoe and bolster. 